I played a coupla games with some old friends yesterday and we discussed this issue over a beer.
Most of us play since 4th edition, even if no one played Eldar, we agreed that being 'touched' by a template was not a common term back then.
Then we did the sensible thing and rummaged around the host's garage for the 4th edition rulebook and what's even better, found it only one beer later.
The catch is, that in 4th edition one had to hit, before placing the blast marker, so a vehicle can't be touched, without being hit first.
Of course these rules aren't used anymore, but it explains the wording used in the Eldar codex a little bit better.
Isn't it funny how you forget those details after a few years. I would have sworn that blast weapons never rolled to hit.
I must rule with eye and claw — as the hawk among lesser birds.